48 GENERAL SCIENCE 



maines. Bacteria develop slowly or not at all at a low tem- 

 perature, or in foods preserved in sugar, vinegar, salt, or by 

 use of smoke. Meats and fruit products, such as catsup 

 and sausage, left exposed for sale day after day without spoil- 

 ing presumably contain chemicals that prevent multiplica- 

 tion of bacteria. These chemicals likewise make the foods 

 kss digestible if not positively harmful. 



It is a part of the varied duties of Food Inspectors to see 

 that no use is made of impure and unwholesome material in 

 the preparation of foodstuffs, however attractive these may 



PIG. 19. Typhoid fever germs highly magnified, and much more in 2 than 



in i. 



be made in appearance and price. The use of any cheaper 

 quality of a substance, or of a cheaper substitute in the 

 preparation of a staple foodstuff, constitutes an adulteration 

 and is prohibited. Any dishonesty in sale of articles under 

 a misleading brand or label is in violation of law. The 

 general principle involved is that while the purchaser has 

 the right to buy whatever he pleases, providing it is not an 

 open menace to health, he needs protection in getting what 

 he pays for so far as its nature, quality, and quantity are 

 concerned. The various States by laws of their own, and 

 in co-operation with the national government through its 

 interstate commerce legislation, seek to prevent wholesale 

 impairment of the health of the nation through its food 

 supply. Upon a rigid enforcement of pure food legislation, 

 and upon the skill of those who make chemical analyses of 



